This is a competing renewal for a two-stage epidemiologic study of the frequency Of and risk factors for major depressive disorder (MDD) and suicidal behaviors in adolescents. Data were collected on three cohorts of students as they progressed from middle through high school and includes a screening sample of 3456 subjects and an interview sample of 589 subjects. Findings suggest relatively high prevalence of depression (9.9%), serious suicide attempts (2.6%) and overall psychiatric disorder (20%) in young adolescents (grades seven through nine) with much lower rates (2.5% major depressive disorder, 1.7% serious suicide attempts and 5.8% overall psychiatric disorder) as students complete high school. Our most recent application supported three and a half years of data collection and a final six months of analyses. The proposed continuation is specifically designed to expand our analyses in the following ways. It will: (1) Provide a detailed comparison of the rates obtained (and the reasons for observed differences) when applying DSM IV versus DSM III criteria for major depression (and other disorders) to the same observations. A comparability ratio will be calculated; (2) Explore the incidence and course of specific depressive symptoms (as opposed to a diagnostic dichotomy) as adolescents move from middle school through high school; (3) Investigate the relationship between a family history of psychiatric disorder on one hand and MDD or suicidal behaviors on the other; (4) Support a more comprehensive exploration of the relationship of baseline (middle school) predictors (including comorbidity) to major depression and suicidal behaviors in the twelfth grade; (5) Determine the ability of depression, depressive symptoms, suicidal behaviors and family environment as ascertained from data during the first three years of the study, to predict future adverse outcomes, including: a) contact with justice system; b) moving vehicle violations; c) academic difficulties; d) truancy; e) alcohol and substance use; f) cigarette smoking; and g) violent behavior. (6) Explore the extent to which earlier ratings rendered by different informants (i.e. mother and adolescent) are useful in predicting future adverse outcomes, including: a) contact with justice system; b) academic difficulties; c) truancy; d) moving vehicle violations; e) alcohol and substance use; f) cigarette smoking; and g) violent behavior. (7) Examine the rate and correlates of mental health service.